After a helping or two it is acceptable to refuse politely or, more simply, just leave a little uneaten food.

在添过一到两次后可以礼貌地拒绝，或更简单的做法是剩下少量未食用的食物以表示吃饱。

youdao

Why did the Germans politely refuse the Korean's invitation to go out for dinner and drinks?

为什么德国人会礼貌地拒绝韩国人出去吃饭和喝酒的邀请？

youdao

One by one, they all started to politely refuse to make a painting of the king.

一个接一个，他们都开始委婉地拒绝为国王作画。

youdao

We continue to wait to be noticed by the GC of Dell, fail to ask for raises at American Airlines, demurely refuse to promote ourselves at Verizon, or politely avoid singing our praises at Kraft.

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